405
FXUS65 KBYZ 130141
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
741 PM MDT FRI JUN 12 2026
KEY MESSAGES
- COLD FRONT THIS EVENING USHERS IN COOLER CONDITIONS AND SHOWER
CHANCES INTO SATURDAY. A FEW THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AND EVENING OVER NORTHERN AREAS.
- LIGHT SNOW ACCUMULATIONS ARE EXPECTED IN THE MOUNTAINS TONIGHT
INTO SATURDAY WITH IMPACTS TO RECREATION AND TRAVEL, INCLUDING
THE BEARTOOTH HWY.
- WARMING AND MOSTLY DRY CONDITIONS SUNDAY INTO TUESDAY.
DISCUSSION
THROUGH THURSDAY...
A SHORTWAVE AND COLD FRONT, ASSOCIATED WITH A PARENT AREA OF LOW
PRESSURE CENTERED OVER FAR NW ONTARIO WILL DROP INTO THE REGION
STARTING LATE THIS AFTERNOON. THIS WILL USHER IN COOLER
CONDITIONS, NORTH TO NORTHEAST WINDS, AND INCREASING SHOWER
CHANCES AS A BAND OF FRONTOGENESIS DROPS SOUTH INTO THE SOUTHERN
MOUNTAINS AND FOOTHILLS. A FEW THUNDERSTORMS ARE POSSIBLE OVER
NORTHERN AREAS THIS AFTERNOON AND EVENING, AND CAMS DO SHOW A
COUPLE HELICITY TRACKS, THOUGH FOR THE MOST PART, WEAK
THUNDERSTORMS ARE ANTICIPATED. ALONG WITH THE BAND OF
FRONTOGENESIS, NORTHEASTERLY UPSLOPE FLOW WILL DEVELOP, FAVORING
THE NORTHERN ASPECTS OF THE SOUTHERN MOUNTAINS AND FOOTHILLS. LOOK
FOR SHOWERS TO INCREASE IN COVERAGE TONIGHT INTO EARLY SATURDAY,
ESPECIALLY OVER THE SOUTH. SHOWERS DECREASE IN COVERAGE BY
SATURDAY AFTERNOON, THOUGH WITH CYCLONIC FLOW IN PLACE, ISOLATED
SHOWERS WILL LINGER OVER PORTIONS OF THE AREA TO THE EVENING. WEAK
INSTABILITY OVER THE REGION MAY ALLOW FOR A FEW RUMBLES. PRECIPITATION
TOTALS LOOK TO RANGE FROM A FEW HUNDREDTHS TO A TRACE OVER THE
NORTH, TO BETWEEN 0.50 TO 1 INCHES OF PRECIPITATION, WITH LOCALLY
HIGHER TOTALS OVER THE NORTHERLY UPSLOPE REGIONS OF THE SOUTHERN
MOUNTAINS/FOOTHILLS. THERE IS A MODERATE TO HIGH CHANCE OF AT
LEAST 0.25 INCHES OF PRECIPITATION SOUTH AND WEST OF A MELVILLE TO
BILLINGS TO ALZADA LINE. SNOW LEVELS LOOK TO FALL AS LOW AS 7,500
FEET SATURDAY MORNING, WITH SOME LIGHT SNOW ACCUMULATIONS
EXPECTED IN THE SOUTHERN MOUNTAINS. GREATEST TOTALS WILL BE FOUND
ON NORTHERLY ASPECTS ABOVE 9,000 FEET. SNOW WILL LIKELY IMPACT THE
BEARTOOTH HIGHWAY, AND HAVE ISSUED A WINTER WEATHER ADVISORY, IN
EFFECT FROM THIS EVENING THROUGH SATURDAY MORNING. PREPARE FOR
IMPACTS TO RECREATION AND TRAVEL IN THE HIGH COUNTRY.
ENSEMBLES GENERALLY DEPICT DRIER NORTHWEST FLOW WITH OCCASIONAL
PIECES OF ENERGY BRINGING ISOLATED SHOWER AND WEAK THUNDERSTORM
ACTIVITY TO THE REGION IN THE AFTERNOONS/EVENINGS SUNDAY INTO
TUESDAY. THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS DURING THIS
TIMEFRAME IS VERY LOW. BY LATE TUESDAY INTO WEDNESDAY, A MORE
ACTIVE WAVE IS POSSIBLE WITH ENSEMBLES DEPICTING ENERGY MOVING THE
REGION IN NORTHWEST FLOW. TEMPERATURES ARE FORECAST TO RANGE
FROM THE 50S AND 60S SATURDAY, TO THE 60S TO LOWER 70S SUNDAY.
TEMPERATURES THEN WARM INTO THE 70S TO LOWER 80S MONDAY THROUGH
THURSDAY, THOUGH TUESDAY COULD SEE TEMPERATURES CLIMB INTO THE
MIDDLE 80S. STP
AVIATION
02Z DISCUSSION...COLD FRONT IS MOVING SOUTH THROUGH THE FORECAST
AREA THIS EVENING SUPPORTED BY A WEST TO EAST ORIENTED JET STREAM
ALOFT. THIS COMBINATION IS LIFTING THE ATMOSPHERE OVER THE WESTERN
TWO THIRDS OF THE FORECAST AREA, WITH CLOUDS INCREASING IN THE
MID LEVELS AND SLOWLY DESCENDING AS THE COLDER AIR AND MORE
EASTERLY LOW LEVEL WINDS TAKE HOLD. EXPECT AREAS OF SHOWERS ACROSS
THE WESTERN TWO THIRDS OF THE AREA THIS EVENING, BECOMING MORE
NUMEROUS BY MIDNIGHT. THIS MORE PERSISTENT LIGHT TO MODERATE
PRECIPITATION WILL CONTINUE THROUGH MID TO LATE MORNING SATURDAY,
ENDING IN THE AFTERNOON HOURS. MVFR CONDITIONS WILL LIKELY BECOME
PREDOMINANT BY 08Z ACROSS THE PRECIPITATION AREAS INCLUDING
KLVM/KBIL/KSHR WITH OCCASIONAL IFR CONDITIONS ESPECIALLY ALONG THE
SOUTHERN FOOTHILLS (KSHR). FURTHER EAST ISOLATED TO SCATTERED
MAINLY LIGHT SHOWER ACTIVITY IS EXPECTED OVERNIGHT INTO THE
MORNING HOURS, BUT CONDITIONS WILL REMAIN MAINLY VFR WITH
OCCASIONAL MVFR CONDITIONS MAINLY ALONG THE MT/WY BORDER ZONES.
SNOW LEVELS WILL DROP TO AROUND FL075 BY SATURDAY MORNING. PERIODS
OF MODERATE MOUNTAIN SNOW WILL KEEP MOUNTAINS AND PASSES OBSCURED
THROUGH AT LEAST MID DAY. CHAMBERS
PRELIMINARY POINT TEMP/POPS
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 049/064 043/070 047/080 055/087 058/076 050/079 051/082
94/W 00/U 00/U 00/N 12/T 11/U 11/B
LVM 041/060 034/068 041/077 048/085 050/076 043/078 044/080
97/T 10/U 00/U 00/N 11/N 11/U 11/B
HDN 047/064 039/070 041/079 051/086 055/074 046/078 049/082
95/W 00/U 00/U 00/N 23/T 11/U 11/B
MLS 048/064 043/072 047/076 051/081 055/072 048/075 050/080
21/B 00/U 00/U 01/E 43/T 11/U 11/B
4BQ 048/061 041/068 045/074 050/081 055/072 048/076 050/081
98/W 00/U 00/U 01/B 33/T 11/U 11/B
BHK 043/061 038/071 043/073 046/076 050/069 044/072 045/078
11/N 00/U 01/N 12/T 44/T 12/W 11/B
SHR 042/058 036/065 038/075 046/081 050/072 043/075 045/079
++/T 11/U 00/N 00/B 12/T 11/U 11/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MDT SATURDAY FOR
ZONE 67.
WY...NONE.
WEATHER.GOV/BILLINGS
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